A high glycaemic response is an elevated blood glucose concentration after eating a meal. Previous studies have found that foods with low glycaemic responses can help prevent type two diabetes, cardiovascular diseases, obesity and cancers.
The study ‘Amaranth, millet and buckwheat flours affect the physical properties of extruded breakfast cereals and modulates their potential glycaemic impact’ was published online ahead of publication in the journal Starch/Stärke.
The research team led by Charles S. Brennan at Lincoln University, New Zealand found that replacing traditional wheat and maize flours in extruded cereals with amaranth, millet or buckwheat flour could lower carbohydrate digestibility, which is linked to the glycaemic impact.
Potential for reduced glycaemic products
“Breakfast cereals containing pseudo-cereal inclusions illustrated a significant reduction in both the readily digestible carbohydrate fraction and the slowly digestible carbohydrate fraction,” said the study.
“This indicates a potential to utilise these grain products in modulating the glycaemic impact to breakfast cereals and hence to produce reduced glycaemic breakfast cereal products,” it continued.
The researchers replaced 65% or 80% w/w wheat flour with amaranth, buckwheat or millet flour to make extruded cereals. They conducted a series of tests to compare the alternative flour products with products made using the traditional flours.
Similar expansion ratio
First they tested each product’s expansion ratio. Ratios for the alternative flour varieties were found to be similar to that of the more traditional flours, with the exception of Amaranth at 65%
“These results illustrate that the inclusion of pseudo-cereals into extruded snack products is possible without significantly affecting product expansion ratio,” said the researchers.
Textural analysis found that the cereals with the alternative flours were similar in texture to the conventional flours.
“This indicates a distinct possibility of utilising these non-conventional grains in the manufacture of extruded snack products without the loss of acceptability in terms of texture,” said the study.
Hydration rates were also tested, which are linked to the bowl life of the cereal product. Amaranth and buckwheat showed reduced rates, which could prolong bowl life.
“The inclusion of amaranth and buckwheat showed that these samples may be of use in reducing the degree of sogginess and disintegration of the product during bowl life,” said the study.
Product and bulk density were also observed. High density values are linked to poor consumer perception.
All alternative flours showed higher density values than the traditional flours, although buckwheat showed a reduced density compared to amaranth and millet.
The researchers said further work would be needed to manufacture breakfast cereals with identical physical characteristics.
The study - Brennan, M. A., Menard, C., Roudaut, G. and Brennan, C. S. (2012), Amaranth, millet and buckwheat flours affect the physical properties of extruded breakfast cereals and modulates their potential glycaemic impact. Starch - Stärke. doi: 10.1002/star.201100150